problem with start up

[HallEffect]

A few days ago my computer just shut off and wouldn't turn back on. However, the mobo green led is on and the optical mouse gets power, but whenever I try starting it up, nothing. i've tried checking all the wires and jumpers to see if it's all still in place but it still won't turn on. It's an asus A8N-SLI. What can I do to fix it?

 

[LA1]

Pull the plug
open her up
reseat the ram and video
plug back in , turn on


if that does not work
unplug
take the ram out
do not put the ram back in
plug in, turn on
if the mainboard, processor, power supply are good
you will hear beeps.

unplug
unplug the hard drive cdrom data and power cables
take out all pci cards not needed to post, like modem.
try again and boot